It is known to simultaneously display video data of multiple video sources. For example, in the field of video surveillance, it is known to simultaneously display the video data obtained from multiple video cameras on a display. For that purpose, the video data of each of the multiple video sources may be displayed in respective viewports on a display. The viewports may be positioned to simultaneously fit a display area on the display. Another example is the video data of multiple remote desktop sessions being simultaneously displayed on a display of a workstation. Each remote desktop session may be displayed in a separate viewport. The viewports may be tiled adjacently or next to each other on the display.
It is also known to spatially scale the video data of one or more of the multiple video sources to fit the respective viewports on the display. For example, the video data of such a video source may be scaled by applying a spatial scaling filter to the video data. Spatial scaling filters are known per se from the field of video processing. For example, nearest-neighbor interpolation, bilinear interpolation, or higher order interpolation filters may be used. Also, non-filter based approaches may be used such as super-sampling.